In January 1922, the Anglo-Irish Treaty was ratified by the Dáil, by a slim majority of 64 votes to 57. de Valera voted against the Treaty and walked out of the Dáil, having resigned as president, thus plunging Ireland into civil war.

Éamon de Valera speaking out against the Anglo-Irish Treaty to a huge crowd in Dublin’s Cork Street in 1922 Public opinion was sharply divided on the treaty and by the summer of 1922, it led to civil war. De Valera survived the Irish Civil War and outlived many of his pro-treaty opponents.